Rodless pump



Aug. 15, 1933. .1. M. sHlMER 1,922,264

RODLESS PUMP Filed Oct. l5, 1931 3 Sheets-Sheet l INVENTOR J. M. SHIMERRODLESS PUMP Aug. 15, 1933.

Filed Oct. l5, 1931 -5 Sheets-Sheet 2 44' Aug- 15, 1933- J. M. sHlMl-:R1,922,264

RODLESS PUMP Filed Oct. l5, 1951 3 Sheets-Sheet 3 @L wm Patented Aug.15, 1933 UNITED STATES PATENT oI-Frcs s claims. (el. 10s- 46) Thisinventiony relates to an improved method of operating a liquid liftingpump for elevating 4liquid from a source deep within a well; and further-to improved pumping apparatus for elevat- 5 ing liquid in a well,the-pumping apparatus being of the type which is actuated by a column ofliquid. More particularly, apparatus embodying my invention may, in theform which I at present prefer, comprise a displacement pump in the welland a reciprocating pump at the surface, the two being connected by acolumn of actuating liquid.

Due to the extreme depth to which wells are being drilled for theproduction of oil. the sucker rod method is no longer satisfactory, andother methods of elevating oil 'from these wells are being sought. Myimproved method of pumping makes it possible to elevate oil with higheiliciency from these deep wells. The pumping is 0 carried on inaccordance with my invention by means of a liquid lifting pump at a lowlevel in the well and actuating means at the surface, the actuatingmeans being connected to the pump by a column of actuating liquid.

In accordance with my invention, a liquid lifting pump is disposed deepwithin a well where a source of the desired liquid is to be found. Thispump is connected to the surfaceby an actuating liquid line or column ofactuating liquid; and in order to obtain high efiiciency in pumping,this column of liquid is balanced by a second column of liquid. Theliquid is pumped from the source by the application of pressure to theactuating column of fluid into a lreservoir 5 chamber and is thereafterintroduced into and and at the same time, a corresponding volume ofliquid is discharged from .the actuating liquidy column at the'surface.

In accordance with my invention, the liquid is discharged from thesystem in timed relation with the cycle of the actuating means. Thepreferred method of actuating the liquid lifting pump disposed withinthe well is to reciprocate the column of actuating liquid. This, Iprefer to do by" apparatus of the cylinder and piston type; and thedischarge of liquid from the column of actuating iiuid at the surfacemay be controlled V-by a valve which is opened and closed in timedrelation with the reciprocations of the piston.

In coordinating the variousparts of my imvproved pumping'system,` I havedeveloped certain 'features `which render the operation of the 515system more uniform and ellicient. The pumping system is primed and theinevitable losses of liquid through leakage, etc. are replacedautomatically from a filler tank. The stroke of the displacement plungeris cushioned so that the momentum of the long and heavy column of liquidshall not cause damage to the displacement appa- V ratus. Thearrangement of parts in my improved construction provides compact andinexpensive apparatus for elevating oil from these great depths.

In the accompanying drawings, in which -I have illustrated schematicallyone form which my invention may take: y C

Figure 1`is a central vertical section through apparatus of thedisplacement type constructed in accordance with the principles ofmyinvention, a reciprocating pump also shown in central vertical sectionbeing connected with the displacement apparatus;

Figure 2 is a similar sectional view showing the position of the partsof the apparatus on the discharge stroke;

Figure 3 is a detail view showing in central vertical section thedisplacement chamber and the discharge passages therefrom;

Figure 4 is a view illustrating the use of a twin cylinder reciprocatingpump for actuating pumping apparatus of the type shown in Figs. 1, 2 and3; and

Figure 5 is a plan view illustrating diagrammatically the connectionswhereby a central actuating means may be connected to a plurality ofwells.

When a pump is disposed close enough to the surface of the ground sothat the pump plunger,

piston or the like may be positively connected toI `a prime mover suchas a steam engine, pumping may be carried on in the usual well knownmanner. When, however, the pump is disposed deep within a well, thepositive connection entails high losses through friction, as forinstance, with a long string of sucker rods. As has 'been abovementioned, wells are becoming increasingly deep; and my improved methodof pumping takes advantage of a column of actuating liquid as asubstitute for the positive connection between the pump. disposed withinthe well and the source of power at the surface.

In order to actuate the pump in the well, I provide mechanism forpushing or, in other suitable fashion, applying pressure to the columnof actuating liquid, so that the same moves downwardly to actuate thepumping apparatus. This column of actuating liquid may attain so great alength, that actuation of the pump cannot be carried on eflicientlywithout a suitable arrangement for again liftingvthis column ofactuating liquid. In accordance Awith my improved method drawn,` thecounter-balancing column moves downwardly and pushes the actuatingcolumn upwardly. By thus alternately pushing the actuating columndownwardly, and causing the same to again move upwardly due to thecounterbalancing column, I am able to elevate liquid from a source deepwithin a well. I prefer to add the pumped liquid to the actuating columnof liquid, each downward movement of the actuating column causing a newincrement to be pumped from the source. As these increments are added tothe column of actuating liquid, corresponding quantities are dischargedfrom the actuating column at the surface.

Inasmuch as the column is intermittently subjected to pressure so as toforce the same downwardly in the well, a discharge valve openingautomatically in response to increases in pressure is not suitable; and,instead, I employ a discharge valve which is timed so as to synchronizewith the cycle of the power means at the surface. Accordingly, thisvalve is closed while the column of actuating fluid is being pushed downthe well, and opens for the discharge of liquid while this column isagain rising in the well.

The process, as thus described, is not dependent upon particularapparatusfor carrying it out. The walls defining the actuating columnand the counter-balancing column may be, in part, the surrounding wallsof the well, or may be separate conduits. Moreover, the type of pumpwhich is disposed in the well may assume various forms.

However, in accordance with anotheraspect of my invention, I haveprovided improved pumping apparatus for thus elevating liquid from asource deep within a well. When the well is drilled, the walls areusually lined with casing; and my improved apparatus is adapted to beused in connection with the casing thus placed in the well.

In Figure 1, the well has been lined with casing 5 extending from thederrick floor 6 to a point well below the level of the oil in the well.Within the casing 5 is disposed a string of tubing 7 having its upperend secured in slips 8.. The upper end of the casing 5 is sealed off bya casing head 9, having an outwardly beveled opening at its upper end.The slips 8 are disposed within the opening and carry at least a portionof the weight of the string of tubing 7.

At the bottom of Figure 1, there is shown a packer 10, carried by thestring of tubing 7. This packer need not be at the very bottom of thewell, but may be positioned at such a point in the casing 5 as toprotect the producing sand. from back pressure. It is quite customary tosupport the packer on a perforated pipe or anchor pipe; but this anchorpipe has been omitted in the drawings, as the structure below the packeris not of importance in connection with the present invention.

Just above the packer 10 is disposed pumping apparatus. This apparatusoperates to lift liquid, such as oil, from the source below the packer10 in the well to the surface. As a preferred embodiment, I have showndisplacement pumping apparatus. The pumping apparatus is connected tothe string of tubing 7 by a nipple 11. To the nipple 11 is connected alength of' tubing 12, per- Iorated at 13. To the lower end of the lengthof tubing 12 is connected a cylindrical member 14 which, in the pumpingapparatus, constitutes the displacement chamber. The upper end of thecylindrical member 14 provides a shoulder on which rests the head 16 ofa servo-motor, which servo-motor includes a liner 17 within the tubing12, this liner constituting the piston chamber of the servo-motor. Inthe embodiment shown, the head 16 and the liner 17 arc formedintegrally. Perforations are formed in the liner 17 registering with theperforations 13; and free communication is thus afforded between thepiston chamber and the annular space surrounding the length of tubing12.

The `displacement chamber is placed in communication with the annularspace surrounding the length of tubing 12 by check valve-controlledpassageways for the discharge of fluid from the displacement chamber. InFigure l, these passageways are marked 18 and extend through the head 16to the lower portion of the piston chamber. Because of this arrangement,only one set of perforations, namely, the perforations 13, is requiredfor placing both the piston chamber and the displacement chamber incommunication with the space surrounding the length of tubing 12. In theconstruction illustrated in the drawings, the passages 18 are controlledby a check valve in the form of a flexible dish-shaped valve 20. Thisvalve is shown in open position in Figure 2.

Between the upper end of the liner 17 and the nipple 11 is an abutmentmember 21, having an axial opening through the same surrounded on thelower side by a raised hub 22. A coiled spring 23 is lodged in theannular recess thus afforded. and provides a cushion for the upwardstroke of the piston 24, which is reciprocable within the pistonchamber. A plunger 25 extends through the head 16 into the displacementchamber and is actuated by the piston 24. In the embodiment shown, theplunger 25 is formed integrally with the piston 24. The downward strokeof the plunger 25 and piston 24 is cushioned by a coiled spring 27,lodged in a recess in a cap member 28 for the inlet valve 29 of thedisplacement pumping mechanism.

This valve 29 is disposed between the cylindrical member 14 and thepacker l0. As illustrated, this valve is a check valve and comprises acasing 30, formed with a valve chamber which communicates with thedisplacement chamber by way of passages 31 through the cap member 28.The valve proper 32 is adapted to lift off its seat to permit upwardflow of oil or other fluid through the packer 10, but seats again byforce of gravity when upward flow stops so as to prevent return of theuid. In the embodiment shown, the seat 33 is formed as a separate memberand is renewable. Upward movement of the valve proper 32 is limited bytransverse pin 34.

It is apparent, therefore, that as the piston 24 reciprocates, theplunger 25 is moved intovand out of the displacement chamber. As theplunger 25 moves out of the displacement chamber, the valve 20 seats andthe valve 32 lifts, oil being drawn up through the packer into thedisplacement chamber. As the plunger 25 descends. the valve 32 seats,and the fluid in the displacement chamber is forced upwardly by way ofthe passageways 18, the lower portion of the piston chamber, and outthrough the perforations 13 into the annular space surrounding thelength of tubing 12. The travel of the piston 24 in both directions iscushioned, the upward stroke being cushioned by the spring 28 and thedownward stroke by the spring 27.

This displacement pumping mechanism being positioned at a depth in thewell too great for proper actuation by a sucker rod, a column of liquidis employed for reciprocating the piston 24 conduit 41 as the volumewhich enters the piston chamber below the piston 24 to lift the samethrough the proper stroke. Inasmuch as .the liquid which passes out atthe top of the tubing 7 from the balancing column is to be received intothe front end of the cylinder 43, it is desirable that the volume ofliquid entering the front end of the reciprocating pump be equal to thevolume of liquid dischargingfrom the piston chamber above the piston 24during the upward stroke of the latter. The ldifference between thevolume entering the piston chamber below the piston 24 to lift the sameand the volume passing out of the piston chamber above the piston 24 isequal to the volume to be discharged from the pumping apparatus.

As a convenient way in which precisely such difference may beestablished on the two sides of the piston 57, I choose a piston rod ofsuch diameter that the volume occupied by the piston rod bears the samerelation to the cylinder 43 of the reciprocating pump that the plunger25 bears to the liner 17 forming the piston chamber of the liquidlifting pump. If we designate the area of the front end of the piston 57by the letter a and the cross-section of the piston rod by the letter b,and designate the effective area of the rear end of the piston rod 57 bythe letter c, then a minus b is equal to c. If we designate the lengthof the reciprocating pumps stroke by the letter d, then aXd: (C-l-b) Xd.

If we designate the area of the top of the piston 24 by the letter e andthe cross-section of the plunger 25 by the letter f, then the effectivearea of the lower side of the piston 24, which I Will designate by theletter g, is equal to e minus f. If the length of the stroke of thepiston 24 and plunger 25 be designated by the letter h, then It will beapparent that as the cross-section of the plunger 25 is decreased, theeffective area of the lower face of the piston 24 approaches more nearlythe area of the top of the piston 24; and.

accordingly, the reciprocating pump is not called upon to exert so greatpressure as is the case when the area of the cross-section ,of theplunger 25 is larger.y On the other hand, the volume of liquid pumped isdirectly proportional to the cross-section of the plunger 25, given thesame length of stroke. Accordingly, when the well is so deep that aconsiderable difference between the area of the top of the piston 24 andthe effective area of the bottom of the piston 24 will require thatgreat pressure be developed by the reciprocating pump, the cross-sectionof plunger 25 may be made relatively small. It should be noted, on theother hand, that the length of the stroke of the plunger 25 may belarge, and, in fact, many times the length of the stroke of thereciprocating pump. As a result, the cross-section of the plunger 25 maybe quite small and the length of stroke correspondingly large, thusreducing the requisite pressure which must be developed by thereciprocating pump. As it is often convenient to deliver a relativelylarge volume of liquid under medium high pressure from the reciprocatingpump, it

will be apparent that it is convenient to thus design the plunger 25with a long stroke and a small cross-section.

As has been above explained, the volume of fluid discharged from therear end of the piston 57 should be substantially the same as the volumeof liquid entering the perforations 13 to lift the piston 24. Shouldthere be an excess of liquid between the rear end of the piston 57 andthe bottom face of the piston 24, excessive pressure might be developedwhen the piston 24 has compressed the spring 23 against the abutmentmember 21. This excessive pressure will be relieved by the valve 41 asabove described. In the same way, the downward stroke of the piston 24is limited by engagement of the plunger 25 with the spring 27; and ifexcessive pressure should be developed within the tubing 7, thisexcessive pressure will be relieved by the relief valve 44. In actualpractice, there will probably be some liquid lost through valves 20 and32 during the reversal of the pump stroke, as valve 32 must seatcompletely before liquid can be elevated in the outer column between thecasing 5 and the tubing 7. This loss may be taken care of by making thepiston rod ofthe piston 57 slightly smaller in diameter than in theorywould be required. Just how large this loss will be can be easilydetermined by experiment.

As has been brought out in the above description, the column ofactuating fluid is forced down the well, and the counterbalancing columnis mainly relied upon for bringing the column of actuating fluid back upthe well. Accordingly, the piston of the power means carries itsprincipal load on the stroke toward the crank shaft. In Fig. 4, I haveshown an arrangement in which a crank shaft is formed with cranks 66 and67 arranged 180 apart. Accordingly, when one piston 68 is being movedinwardly, the other piston 69 is being moved outwardly. This balancesthe power requirements on the crank shaft 65. 'Ihe piston 68 may actuatea liquid-lifting pump in the well 70, and the piston 69 may actuate aliquidlifting pump in the well 71. It is apparent that during theportion of the cycle of the crank shaft 65 during which the piston 68 isunder heavy load, the piston 69 is under light load and vice versa.

Quite frequently, wells flow slowly, and it is' desirable to pump agiven well for only a portion of the twenty-four hours. For this reason,it is customary in many oil fields to provide a central pumping powerWhich may be connected up to one, two or three of a plurality of wellsat a time. When a given Well has been pumped for a sufficient number ofhours, the connection is changed to the pump for pumping another well.My invention is adapted for this type of pumping; and in Fig. 5 I haveshown an arrangement whereby a central power means may be connected toany one of a plurality of Wells for actuating a liquid-lifting pump inthe same. In this figure, a reciprocating pump 73 is shown; and at.various places are located wells '74, 75, 76, 77, etc. A central Valvemechanism 79 is connected by a pair of conduits 8G and 8l to each of thewells. The two ends of the cylinder of the pump 73 are connectedrespectively to the valve mechanism 79 by pipes 82 and 83. In Fig. 5, acontrol element is shown diagrammatically at 84 whereby pipe 82 may beconnected to any one of the pipes 80. At the same time, the pipe 83 willbe connected to the corresponding pipe 81. It is apparent, therefore,that by suitable manipulation of the control element 84, the power means73 may be connected for actuating any one of the wells.

In the course of the above description, certain advantages of myimproved pumping mechanism have been pointed out. In addition, it shouldbe noted that due to the necessity of forcing the column of actuatingliquid downwardly in the well, it is important that a valve be employedwhich is properly timed. By actuating the rotary valve 51 from the crankshaft 56, I have provided timing means which causes the discharge ofiiuid from the pumping apparatus at the proper time in the cycle of thisapparatus. The apparatus -itself is of improved construction, the pistonoperating eiliciently to pump oil out of the well and having its strokecushioned so as to save the apparatus from danger of jolts.

The use of the packer 10 has the great advantage of preventing pressurefrom acting on the sand so as to cause the oil to back up. The oil mayflow freely into the displacement chamber during the upward stroke ofthe. piston 24; the check valve 32 seats during the downward stroke ofthe piston 24, and accordingly there is no possibility of' any backpressure being placed on the producing sand. The packer 10 prevents thepressure of the actuating uid from making its way down between thecasing and the outside of the pumping apparatus.

My improved pumping apparatus is compact, and the power from thereciprocating pump is used eiciently to pump fluid from-the depths ofthe well up to the surface. The eiciency of the apparatus is maintainedby keeping the string of tubing lled with fluid from the filler tank 43.

While I have illustrated and described a preferred arrangement ofapparatus for elevating liquid in a well and have shown a specicconstruction of such apparatus, it will be understood that the inventionis not restricted to the particular construction or arrangement shown,but may be variously modified within the contemplation of the inventionand under the scope of the following claims. L 1

I claim:

l. In well pumping apparatus, in combination, a liquid liftingpump ofthe displacement type disposed adjacent the bottom of a well, fluidcolumns to actuate said pump extending therefrom to the top of the well,a reciprocating pump disposed adjacent the top of the well andvoperatively connected to said columns to apply'pressure alternatelythereto to actuate said pump, means in said liquid lifting pump todisplace well fluid into one of said columns, means to maintain thevolume of the other column substantially constant, and rotary valvemeans adjacent the top of the well operatively connected in synchronismwith the said reciprocating pump to permit the discharge from the saidfirst column of a volume of fluid substantially equivalent to thatdisplaced-therein by the said liquid lifting pump.

2. In well pumping apparatus, in combination, a liquid liftingpumpdisposed adjacent the bottom of a well, said pump comprising two alignedcylinders having a diameter adapting them to be disposed within a wellcasing, means toseal the outer periphery of the lower cylinder to thesaid Well casing, a valved opening in the bottom of said lower cylinderto permit a controlled flow of welldluid into said lower cylinder, avalved opening in the top of said lower cylinder into the bottom ofl theupper cylinder to permit a controlled ow of well fluid from the lowercylinder into the upper cylinder, a pumping piston disposed in the upperchamber, a plunger oper.- atively connected thereto and adapted to bereciprocated into and out of said lower cylinder upon reciprocating ofsaid piston, a line of tubing concentrically disposed within the wellcasing closing the upper end of said upper cylinder, a plurality ofopenings adjacent the bottom of said upper cylinder opening into theinterior of said well casing, iiuid columns contained in said casing andconcentric tubing extending to the top of the well, means adjacent thetop of the well to alternately apply pressure to said columns toreciprocate said piston up and down within the said upper cylinder, andvalve means synchronized with said pressure applying means to permit thedischarge from the casing uid column of a volume of fluid substantiallyequivalent to that displaced therein from the said lower cylinder.

3. In well pumping apparatus of the type described and claimed in claim2, in which the means to apply pressure to the actuating uid columnscomprises a reciprocating pump and the valve means comprises a rotaryvalve operatively connected in synchronism with said pump.

4. In well pumping apparatus of the type described and claimed in claim2 including means l to maintain the volumes and pressures of thc twopiston actuating fluid columns substantially constant. n

5. In well pumping apparatus of the type described and claimed in claim2, in which the means to apply pressure to the actuating uid columnscomprises a reciprocating pump and in which the areas of the two workingfaces of the liquid lifting pump piston and the areas of the two workingfaces of the reciprocating pump piston are proportioned with respect tothe working loads thereon.

6. In deep well pumping apparatus, a liquid lifting pump adapted to bepositioned at the bottom of a well and to be actuated by uid columnsextending thereto. from the, top of the Well, said pump comprising apair of aligned cylinders adapted to be enclosed by the Well casing,means to seal the bottom cylinder to the said well casing, a checkvalved opening in the bottom of the lower cylinder to permit acontrolled flow of well uid into said cylinder, check valved openings inthe top of said lower cylinder to permit controlled flow of uid from thelower cylinder into the upper cylinder, openings in the lower part ofthe upper cylinder to permit free ingress and egress of iluid from thecasing into and out of said upper cylinder, -a string of tubing openinginto the top of said upper cylinder and extending concentrically withinthe casing to the top of the well, a pumping piston disposed in theupper cylinder and a plunger member extending therefrom into the lowercylinder, said plunger being adapted upon a reciprocation of said pistondownwardly and upwardly within said cylinder to be inserted into and tobe with drawn from said lower cylinder, a column of fluid I in saidcasing about said string of tubing and a column of fluid in said tubing,means adjacent the top of the well to apply pressure alternately to saidfluid columns to reciprocate said piston within the upper cylinder, andvalve and pressure release means to control the amount of iluid in eachcolumn to maintain the said amount substantially constant.

JOHN M. SHIMER.

